In a conventional keyless entry system, each actuator of a door lock mechanism of a vehicle is operated by a wireless remote control unit so that the doors of the vehicle can be locked/unlocked at a place remote from the vehicle. According to this keyless entry system, it is general that plural switches are provided on a transmitter for wireless operation at Such a manner that each operating switch has its own function. For example, all the doors are unlocked by switch operation on a door unlock switch.
However, if all the doors are unlocked by switch operation on the door unlock switch, a stranger (unauthorized person) may get into the vehicle from the assistant driver's seat side when an authorized user gets into the driver's seat after the doors are unlocked. Therefore, it is proposed that only the door at the driver's seat side is unlocked by the first switch operation and then all other doors are unlocked by the subsequent switch operation.
Furthermore, in another entry system, that is, a smart entry system, a user carrying a portable unit (containing a wireless device) can open the doors of a vehicle by merely touching a door handle of the vehicle under the state that he/she approaches vehicle. This system is already practically used in vehicles, etc. According to the smart entry system, when a user having a portable unit which can make mutual communications with a transmitter provided in each door or the like of the vehicle approaches the vehicle and enters a predetermined area, so that predetermined communications are made between the transmitter and the portable unit, the doors of the vehicle are set to an unlock standby state. Then, when the user touches the door handle provided with the transmitter under the unlock standby state, the door concerned or all the doors are unlocked. The doors can be locked by switch operation of a separately provided door lock switch.
In the smart entry system, the twice-operation unlock specification is required for the purpose of enhancing the security performance as in the case of the keyless entry system. A system in which a lock switch is also used in an unlock operation is known as a smart entry system to which the twice-operation unlock specification is applied (for example, Owners Guide—Infiniti FX45/FX35 2004), Third Chapter (pp 3-13),
Specifically, when a door lock switch is operated once first under the unlock standby state, only the door at the driver's seat side is unlocked. All other doors are unlocked by switch operation on the lock switch again within a fixed period (for at Stance, 5 seconds). When the switch is operated again, all the doors are locked again. Furthermore, when the switch is operated once and the fixed period elapses under the state of unlocking of the door at the driver's seat side, the door is locked again.
In the above twice-operation unlock control, only the driver's seat door is first unlocked, and then all the doors are subsequently unlocked. However, when it is required to unlock the door at the driver's seat side by switch operation of the lock switch once and then immediately lock the door, the door concerned is locked after all the doors are temporarily unlocked. That is, even when it is unnecessary to unlock all the doors for the user (the user does not want to unlock all the doors), it is necessary to temporarily unlock all the doors in order to lock his/her desired door. Thus, an operation contrary to the user's intention is necessarily carried out.
Therefore, for example, in a case where a user finds a stranger at the assistant driver's seat side when he/she is about to unlock the driver's seat door and get into the vehicle (open the door), the user twice operates the lock switch to immediately lock the driver's seat door again. However, at this time, all the doors are temporarily unlocked. Thus, the stranger may get into the vehicle from the assistant driver's seat side.
Therefore, if the twice-operation unlock specification is not applied to the unlock operation based on the switch lock operation, but applied to the existing smart entry system in which a door is unlocked by touching the door handle of the door, the user could immediately lock the driver's seat door by switch operation of the lock switch when he/she wants to immediately lock the driver's seat door under the state that only the driver's seat door is unlocked.
Various kinds of touch sensors such as an electrostatic capacitance type touch sensor, an optical type touch sensor, etc. are normally used for detecting a user touch to the door handle. It is thus very difficult for these touch sensors to clearly discriminate the first touch and the subsequent touch from each other.
Therefore, if the twice-operation unlock specification is directly applied to the existing smart entry system, it is likely that the touch sensor side determines that the door handle is touched twice (or more) although the user believes that he/she touched the door handle only once, and thus all the doors are unlocked against a user's intension. If so, even if the user finds a stranger when unlocking only the driver's seat door and thus hastens to lock the door again by the lock switch, the state before the locking may actually be an all-doors unlocked state. In this at Stance, the stranger may get into the vehicle without difficulty.